From 86469bdd32a7cb57db64228e5d4f5a0e1bb80c72 Mon Sep 17 00:00:00 2001
From: Michael Telatynski <7t3chguy@gmail.com>
Date: Wed, 28 Feb 2024 13:02:09 +0000
Subject: [PATCH] Add custom reporter to auto-report flaky Playwright tests
 (#12290)

---
 .github/workflows/end-to-end-tests.yaml |  5 +-
 playwright/flaky-reporter.ts            | 85 +++++++++++++++++++++++++
 2 files changed, 89 insertions(+), 1 deletion(-)
 create mode 100644 playwright/flaky-reporter.ts

diff --git a/.github/workflows/end-to-end-tests.yaml b/.github/workflows/end-to-end-tests.yaml
index 54ddb40006..3228fe91b3 100644
--- a/.github/workflows/end-to-end-tests.yaml
+++ b/.github/workflows/end-to-end-tests.yaml
@@ -156,7 +156,10 @@ jobs:
                   merge-multiple: true
 
             - name: Merge into HTML Report
-              run: yarn playwright merge-reports --reporter=html,github ./all-blob-reports
+              run: yarn playwright merge-reports --reporter=html,github,./playwright/flaky-reporter.ts ./all-blob-reports
+              env:
+                  # Only pass creds to the flaky-reporter on main branch runs
+                  GITHUB_TOKEN: ${{ github.event.workflow_run.head_branch == 'develop' && secrets.ELEMENT_BOT_TOKEN || '' }}
 
             - name: Upload HTML report
               uses: actions/upload-artifact@v4
diff --git a/playwright/flaky-reporter.ts b/playwright/flaky-reporter.ts
new file mode 100644
index 0000000000..3d358bb74d
--- /dev/null
+++ b/playwright/flaky-reporter.ts
@@ -0,0 +1,85 @@
+/*
+Copyright 2024 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+/**
+ * Flaky test reporter, creating & updating GitHub issues
+ * Only intended to run from within GitHub Actions
+ */
+
+import type { Reporter, TestCase } from "@playwright/test/reporter";
+
+const REPO = "element-hq/element-web";
+const LABEL = "Z-Flaky-Test";
+const ISSUE_TITLE_PREFIX = "Flaky playwright test: ";
+
+class FlakyReporter implements Reporter {
+    private flakes = new Set<string>();
+
+    public onTestEnd(test: TestCase): void {
+        const title = `${test.location.file.split("playwright/e2e/")[1]}: ${test.title}`;
+        if (test.outcome() === "flaky") {
+            this.flakes.add(title);
+        }
+    }
+
+    public async onExit(): Promise<void> {
+        if (this.flakes.size === 0) {
+            console.log("No flakes found");
+            return;
+        }
+
+        console.log("Found flakes: ");
+        for (const flake of this.flakes) {
+            console.log(flake);
+        }
+
+        const { GITHUB_TOKEN, GITHUB_API_URL, GITHUB_SERVER_URL, GITHUB_REPOSITORY, GITHUB_RUN_ID } = process.env;
+        if (!GITHUB_TOKEN) return;
+
+        const body = `${GITHUB_SERVER_URL}/${GITHUB_REPOSITORY}/actions/runs/${GITHUB_RUN_ID}`;
+
+        const headers = { Authorization: `Bearer ${GITHUB_TOKEN}` };
+        // Fetch all existing issues with the flaky-test label.
+        const issuesRequest = await fetch(`${GITHUB_API_URL}/repos/${REPO}/issues?labels=${LABEL}`, { headers });
+        const issues = await issuesRequest.json();
+        for (const flake of this.flakes) {
+            const title = ISSUE_TITLE_PREFIX + "`" + flake + "`";
+            const existingIssue = issues.find((issue) => issue.title === title);
+
+            if (existingIssue) {
+                console.log(`Found issue ${existingIssue.number} for ${flake}, adding comment...`);
+                await fetch(`${existingIssue.url}/comments`, {
+                    method: "POST",
+                    headers,
+                    body: JSON.stringify({ body }),
+                });
+            } else {
+                console.log(`Creating new issue for ${flake}...`);
+                await fetch(`${GITHUB_API_URL}/repos/${REPO}/issues`, {
+                    method: "POST",
+                    headers,
+                    body: JSON.stringify({
+                        title,
+                        body,
+                        labels: [LABEL],
+                    }),
+                });
+            }
+        }
+    }
+}
+
+export default FlakyReporter;